Measuring 4-Limb Blood Pressure is not a Reliable Discriminator in Neonatal Heart Murmur Assessment

Background: Heart murmurs are commonly found during routine neonatal examination at postnatal ward, with an incidence of 0.6 - 1.4%. Measuring 4 limb blood pressure alongside of checking femoral pulses and pre and postductal saturation was part of initial assessment of babies with heart murmur.

Objectives: To assess the effectiveness of 4 limb blood pressure as a reliable discriminator between pathological and innocent heart murmurs in Newborn babies with heart murmur.

Methods: We found heart murmur in 52 babies over a period of 12 months (2017-2018) during routine baby check at postnatal ward at University Hospital Lewisham. Following thorough physical examination of all babies with neonatal heart murmur, we checked femoral pulses, pre and post ductal oxygen saturations and 4 limbs blood pressure as part of their assessment for heart murmur. All babies with normal saturation and femoral pulses were assessed again at neonatal follow up clinic after 4 weeks. Babies who had still heart murmur were referred to paediatric cardiology clinic for further assessment including echocardiography.

Results: The incidence of heart murmur in babies was 1.3%. All babies had normal pre and postductal saturation and femoral pulses. Almost in 50% of babies’ upper limb mean blood pressure (MBP) was higher than lower limb MBP. Almost all babies with heart murmur had a patent foramen ovale (PFO). Only 1 patient had aortic regurgitation on echocardiography.

Conclusion: Measuring 4 limb blood pressure in babies with heart murmur who have normal oxygen saturation and normal femoral pulses does not add any additive value in assessment of babies with heart murmur.